Regenerative sound recording device



June 18, 1935 B. KWARTIN I REGENERATIVE SOUND R CORDING DEVICE Filed Feb. 3, 1931 Patented June 18, 1935 Z @5,4Z5

diA'iES PATENT i -rice REGENERATIVE SOUND RECORDIN DEVICE Bernard Kwartin, Brooklyn, N. Y.

Application February 3, 1931, Serial No. 513,100

6 Claims. (Cl. 179100.3)

This invention relates generally to improveof this invention to produce a photographic ments the art of recording sound and more rd of sound vibrations which is characterized particularly to a regenerative sound recording by the fact that the areas of the photographic device for recording sounds upon a photographic rep ese tat o s of t e respective sound afilm. tions vary in accordance with; the changes in the 5 It is among the principal objects of the present nte t es Of said V bra ns. invention to provide a sound recording device Ot r O j ct d advantages of the Present which is operative to convert electrical current invention w app mere fully hereinaftervariations into corresponding light variations and The invention Consists substantially in the which is capable of producing greater iati combination, construction, assembly and relative 10 in the light intensity with a minimum of current arrangement of p all 2175 will be more u y amplification. hereinafter described, as shown in the accom- A still further object of the invention is the Denying d and as finally Pointed Outin t e provision of a sound recording device including pp d claims- In the accompanying -wprimary and secondary sources of light operative which is more less a ati a d 15 to conjointly produce light rays the intensities merely illustrative of the general p p es Ci of which vary in accordance with the sounds as the iI1VeI1ti0I1I originally produced, the primary source being in- Figure 1 is a diagrammatic View S wi an cluded in a microphone circuit from which it r n f r p s -p y recording derives its energy and the secondary source being Sounds up a traveling film in accordance with 20 included in an electrically independent photoprinciples of this inVeiltiOh; electric cell circuit in which current variations Figure 2 is a diagrammatic View Of a g y are established in accordancefwith the variations modified arrangement f the pp u in intensity of the primary light source. Fi e 3 i a diagrammatic v w win an Still another object of the invention is the arrangement f ph s p y recording 25 provision of a sound recording device which has Sounds Upon a film in accordance With the p an increased range of sensitivity and soundshadp s 0f e P e invention; ing capacity, which is adapted'to regeneratively Figure 4 is an e t e a Of a p e e d produce light fluctuations in fixed accordance f m of p at shutt rs r p du th with the initially produced sounds, and which is desired photogr phi r p n ion of th 30 capable of recording the strongest and weakest sounds be recorded; sound effects without exaggerated amplification. ig 5 is an enlarged View Of One Of t hu Still another objectof the invention is the proters shown in Figure 4 and its associated electrovision of an improved shutter arrangement for e variably intercepting the light rays, this shutter Figure 6 is a view taken on the line 6-6 of 35 arrangement being of such design and operable Figure 5; and in such manner as to produce upon the photo- Fi ure 7 i an a d fragmentary w Of graphic film a sound record in the form of a a photographic sound record Obtained by using series oi bands or striations of substantially ellipthe shutter arrangement of Figures 3 and 4. 40 tical form, both the major and minor axes of "Referring now totthe drawing and more par- 40 each of which increase or decrease accordingly ticularly to Figure 1 thereof which shows an aras the intensity of the sound vibration is inrangement for photographically recording sounds creased or decr ased. The present arrangement upon a traveling film it, it will be observed that for photographicaliy recording sounds thus takes the sounds which, are to be recorded upon this into account not only the intensity differences film are initially received by a suitable microin the photographic representations of the sounds ph e ll similar device which is adapted but also the-differences in amplitude. to convert the sound vibrations as originally A still further object of this invention is the produced into corresponding electrical current provision of an improved photographic record variations. These current variations, which of sounds which consists of a series of longiare thus set up in the microphone circuit, may .50 tudinally spaced bands or striations the longibe suitably amplified, as at l2, preliminarily tudinal and transverse dimensions of which both to energizing an actinic lamp 33 or other source increase or decrease in accordance with the vaof light capable of producing light rays of varyriations in intensity of the sounds as originally ing intensity. It will be understood, of course, produced. In other words it is among the aims that the intensity of the light rays which ema- 55 ring from both sources.

nate from the primary source of light 13 is entirely dependent upon and is in accordance with the current variations established in the microphone circuit I2,

Heretofore and prior to this invention it has been the usual practice to employ a source of light, such as an actinic lamp, which is energized by the current variations established in the microphone circuit. The results obtained through the use of this single source of light have been far from satisfactory due to the fact that an exaggerated amount of amplification was necessary in order to obtain the required intensity of light. This not only necessarily entailed overloading of the actinic lamp, but it also considerably reduced the sensitivity of the lamp to current variation extending over a wide range. In other words, because of the exaggerated amplification necessary to produce light rays of maximum intensity corresponding to the strongest sound effect, it has been exceedingly difiicult, if not entirely impossible, to produce light rays of such minimum intensity as are necessary to faithfully record those sounds of weakest or finest character.

The present invention overcomes these difficulties heretofore encountered by employing a secondary source of light which is also capable of producing light rays of varying intensity. Preferably, this secondary source of light is included in a circuit which is electrically independa ent of that which includes the primary source of light l3, this secondary source of light being designated in Figure 1 by the reference numeral M. As appears quite clearly in Figure 1 both the primary source of light l3 and the secondary source of light [4 are suitably housed'within a casing l5 having an opening I6 through which are commonly projected the light rays emanat- Also housed within the casing 15 and adapted to be influenced by the light rays emanating from the primary source of light it is a photo-electric cell 11. This photo-electric cell If, which is connected to a suitable source of electrical energy I8, is included in any suitable type of amplifying circuit l9 for supplying a variable current to the secondary source of light M. It will of course be apparent that the variations in intensity of the light rays :produced by this secondary source of light are in strict accordance with the variations in the light rays produced by the primary source of light l3. The light rays thus produced by the secondary source of light are added to those produced by the i :primary source of light in such manner that the resultant light rays which are projected through smaller capacity than in those cases where it is the sole source of light. On the other hand, the secondary source of light 14 may be of any desired capacity greater than that of the lamp l3, or any number of secondary sources of light may be employed as is illustrated in Figure 2 wherein a pairof secondary lamps 26 are employed. If desired, the secondary lamp may be respectively provided with suitable reflectors 2! arranged for the purpose of directing a more concentrated light through the opening in the casing and upon the traveling photographic film.

It will be apparent that the arrangement just described affords what is in effect a regenerative sound recording lamp inasmuch as the light variations which are produced by the primary lamp i3 are reconverted into corresponding electrical variations, which latter variations after being suitably amplified are employed to energize the secondary lamp Hi. The light variations thus produced by the secondary lamp I4 are not only additive with respect to those produced by the primary lamp but are also employed to further influence the photo-electric cell ll, thereby still further decreasing the resistance of this cell and causing the current in the secondary lamp circuit is to be increased proportionately as the resistance in the photo-electric cell is decreased. This cycle of operation continues until the resistance of the photo-electric cell has been reduczd to an irreducible minimum with the consequent result that a maximum flow of current is obtained for energizing the secondary lamp M of Figure 1 or the secondary lamp 259 of Figure 2.

The advantages of the present invention will be quite apparent inasmuch as it makes possible the photographic recordation of sound in such manner that the nuances between sounds of strongest and weakest character are defined in a manner not heretofore possible. Thus, where the sounds as originally produced are quite feeble in character, the primary lamp I3 which is of relatively small capacity, will produce light variations which are correspondingly feeble in character but which are nevertheless sufficiently strong to influence the photo-electric cell IT in such manner as to effect the energization of and so produce light rays from the secondary lamp M which, when added to the light rays produced by the primary lamp it, are sufficient to produce a faithful record upon the photographic film of these feeble sounds. One the other hand, when the sounds as initially produced are quite strong in character, the primary lamp I3 is correspondingly energized to produce light rays of strong intensity which in turn strongly influence the photo-electric cell to produce strong light in the secondary lamp i l. The strong light effects so obtained in the lamps l3 and I4 are produced without energizing the primary light source to a degree beyond its capacity and without entailing any undue or exaggerated amplification in the energizing circuit for the primary lamp.

Referring now more particularly to Figure 3, it will be observed that a shutter arrangement has been provided for variably intercepting the l ght rays which emanate from within the interior of the casing l5. These light rays may be produced 1 either by means of an actinic lamp 22 which is variably energized in accordance with the initially produced sound variations in the usual manper well known in the art or by the regenerative principle as shown in Figures 1 and 2 hereinbefore. opening it in the casing l5 are a pair of shutters 23, these shutters being movable in parallel planes and toward and away from each other. As more clearly appears in Figure 4 each of these shutters, which are preferably constructed of an opaque material, is provided with an arcuately P shaped inner end 2 5. By reason of this construction, it will be apparent that as these shutters are shifted toward or away from each other to effect a more or less overlapping relation between the curved inner ends thereof a greater or smaller Arranged immediately in advance of the opening 25 of substantially elliptical-formis afforded through which the light rays may pass for" projection upon the photographic film.

Obviously, in order to obtain a faithful photo-- graphic representation of the soundsas initially produced, it is imperative that the shutters 23 operate in exact synohronism with the current variations established in the microphone circuit for energization of the actinic light source. In

order to secure synchronous actuation of magnetic field. As appearsquite clearly in Figure 3 each of the shutters 23 has operatively associated therewith an electromagnet 26 which is energized by the passage of an electric current through the stationary coil 21. The electromagnet movable 001168 to which is suitably secured one of the shutters 23. Each of these coils 3| is connected in parallel with the light source 22 in such manner that this light source and both of the movable coils are simultaneously energized by the current variations which are set up in accordance with the sound vibrations as initially pro duced. Energy is supplied to the stationary coils 28 from a suitable source of supply, such as a battery 3! It will be understood that current passing through the movable coils 30 render the same magnetic in consequence of which they tend to move within the magnetic field created between the poles 29 of the electromagnet. Inasmuch as the current value changes in these coils in accordance with the variations in the sound vibrations, there is produced a change in the magnetic field of each movable coil. Due to the reaction which takes place between the changeable magnetic field of the movable coil and the constant magnetic field of the stationary coil the former is set in motion and moves toward and away from the stationary coil in accordance with the current variations established in the microphone circuit. This movement of the coils 30 is imparted to the shutters 23 which are respectively secured to the coils with the result that a greater or less opening is provided between the proximate ends of the shutters through which the light rays emanating from the light source 22 may pass.

Inasmuch as both of the coils 38 are dependent for their energization upon the same current variations which are employed to energize the light source. irrespective of whether the latter is of the simple form shown in Figure 3 or the regenerative arrangement shown in Figures 1 and 2, it will be apparent that the shutters 23-23 will be caused. to move away from or toward each other whereby to provide a substantially elliptical opening between the overlapping ends thereof the area of which varies in strict accordance with the current variations and the sound vibrations corresponding thereto. It will be understood of course that the proximate ends of the shutters 2323 may be shaped other as shown to produce a sound record which is comparable in every respect with that shown in Figure 5, as by providing V-shaped notches in the ends of the shutters Also surrounding the central core it of each electromagnet is a small which together fuhctio n to provide a diamondshaped opening of variable longitudinal and transverse dimensions. a

Figure 5 is an enlarged fragmentary view of a sound record such as may be produced by the arrangement shown in Figure 3 and wherein are employed the shutters illustrated in Figure 4. It will be seen that this record is-made up of a series of longitudinally spaced bands or striations 32 each of which is of substantially oval or elliptical shape with the major axes thereof ex tending transversely of the film. It will further be noted that longitudinal'and transverse dimensions of each striation (i. e. the minor and major axes thereof) vary accordingly as 'the- 5 value of the current supplied to the light source is varied. Thus, where the initially produced sound vibration is of great strength the longitudinal and transverse dimensions of the photographic record thereof are both greater than are the corresponding dimensions of the photographic record of a weaker sound vibration. I

The advantages of the type of record shown in Figure 5 will be quite apparent inasmuch as it makes possible the recordationof sound effects upon the film which take into account the photo graphic representations of both the intensity and amplitude differences between the sounds. The result is the provision of a photographic record of sounds wherein the nuances between sound vibrations of greatest and weakest character are rendered larger, richer and clearer than has been possible heretofore.

It will be understood of course that various changes may be made from time to time in the .the latter into corresponding electrical current variations, a light source arranged to be variably energized by said current variations for producing light variations corresponding to said sound variations, a pair of cooperating shutters arranged in advance of said light source and movable toward and away from each other, the innor ends of said shutters being relatively so arranged and complementally formed that upon movement of said shutters relatively to each other there is formed therebetween an opening variable in depth and in width, and means for effecting the movement of said shutters relatively to each other accordingly as the intensity of the said light source is varied.

2. In an apparatus for photographically recording sounds upon a photographic film, in combination, means variably responsive to sound variations for recording the same upon the film, light intercepting means arranged in advance of the film and provided with an aperture of variable width and depth, and means energizable commonly with said sound responsive means and movable in a fluctuating magnetic field for varying the width and depth of said aperture, the changes in said magnetic field being dependent upon said sound variations.

3. In an apparatus for photographically recording sounds, in combination, sound responsive means for converting the sounds into corre-' sponding electrical current variations, means variably energizable by said current variations for producing light rays of varying intensities, a pair of coacting light intercepting screens complementally formed to provide an aperture of substantially biconvex form through which the light rays may pass, means for creating a constant magnetic field in the immediate vicinity of each of said screens, a pair of electromagnetic coils respectively located within said constant magnetic fields and secured to said screens, said coils being commonly energized by said current variations whereby to create changeable magnetic fields therein to vary the relative position of said screens and so change the effective dimensions of both the major and minor axes of said aperture.

4. In an apparatus for photographically producing a sound record upon a photographic film, in combination, a sound responsive device, a light producing element variably activated by said sound responsive device forrecording the sounds upon a film, a pair of light intercepting shutters arranged between said light producing element and said film, the proximate ends of said shutters being complementally formed to provide an opening of greater width than depth and wherein the depth-gradually decreases in opposite directions from the center thereof, and means for varying the relative-position of said shutters whereby to increase or decrease the eiiective dimensions of said opening as respects both the width and the depth thereof in accordance with the variations in the sounds as originally produced.

'5. The method of producing a photographic record of sound vibrations which consists in passing a photographic film before a source of light which varies in intensity in accordance with the variations in said sound vibrations and simultaneously exposing to said light successive areas of said film which vary both in horizontal and vertical dimensions accordingly as the intensity of said light varies.

6. The method of producing aphotographic record of sound vibrations which consists in passing a photographic film before a source of light the intensity of which varies in accordance with the variations in said sound vibrations and simultaneously exposing to said light successive areas of said film in each of which the length of the major and minor axes are both correspondingly increased or decreased accordingly as the intensi- $5 ty of said light is increased or decreased.

BERNARD KWARTIN. 

